The present invention relates to a submersible pump arrangement and more particularly to a coupling system for a submersible pump assembly adapted to be coupled to and decoupled from a discharge conduit immersed in a liquid receiving wet well.
It has heretofore been proposed to provide a detachable coupling system for a submersible pump assembly to effect coupling and decoupling thereof from a discharge conduit adjacent the bottom of a wet well without need of access by an operator to the bottom of the wet well. Such a coupling system is desired because the submersible pump assembly is typically immersed under brackish water or sewage. The decoupling of the pump assembly and the removal of same from the wet well is periodically necessary for service. Thus, it is a well known practice to provide a detachable coupling system that permits the raising and lowering of a submersible pump assembly from a wet well without the unbolting of any piping.
It has been the heretofore practice to provide a self aligning wedge connection between the submersible pump assembly and a base elbow pipe which communicates with the discharge conduit. However, upon lowering of the submersible pump assembly, there must be some type of guide rail system to guide the faces of the coupling into alignment and connecting seal with the base elbow pipe. Prior solutions have incorporated various guide rail arrangements. All of such arrangements are quite similar, in that separate guide rail structural members are provided whose sole purpose is to guide the submersible pump assembly into connection with the base discharge elbow. These guide rails typically extend into the wet well and are positioned either adjacent to the pump discharge flange or adjacent to the pump volute. The pump assembly is typically provided with recesses that fit partially around the guide rails so that the pump assembly will follow the rails as it is raised and lowered. Examples of such systems are disclosed in U.S. Pat. Nos. 3,427,982, 3,656,871 and 4,392,790.
Such guide rail arrangements have several disadvantages. The guide rails are typically of small diameter and tend to bend if the pump does not lift evenly. The addition of guide rails into the wet well presents additional members that tend to collect rags, paper, plastic bags, etc. The installing contractor has additional pieces to install and keep track of. The guide rails and attachments increase the cost of the system.